1. Field of the Invention
The invention relates to a device for treatment of body tissues. More particularly, the present invention relates to an apparatus and method for treatment, including vaporization and coagulation, of body tissues using an electrode comprising a porous, foam-like material in conjunction with a conductive fluid such as saline.
2. Description of Related Art
Electrosurgery has been used for treating body tissue, including coagulation, desiccation, and vaporization of tissue. A common method of performing electrosurgery involves injecting conductive fluid, such as saline solution, into the operational site. The conductive fluid serves to create an electrical path between the electrodes and the body tissue.
Continuous replenishment of the conductive fluid can be important during various procedures. The fluid can be absorbed by the patient's body. Furthermore, fluid may become contaminated, thus compromising its conductivity and/or other desirable characteristics, such as clarity.
When sufficient power is applied to an active electrode in the presence of a conductive fluid and body tissue, the electrical current will flow from the active electrode, through the conductive fluid, and into the tissue. The electrical power can cause various tissue effects, including coagulation, necrosis, and desiccation.
Various electrode configuration are known for spot treatments of body tissues. Many prior art electrode assemblies include a stiff metal active electrode, which is generally rigid and non-yielding. A surgeon can push the active electrode of such rigid configurations into the tissue to be treated, thereby reaching tissues that are beneath the natural tissue surface.
For treating a generally uneven tissue surface, a brush electrode is known that is formed from numerous wires, each of which acts as an active electrode. As the brush is drawn across the tissue surface, the individual brush wires generally follow the tissue surface.
In some applications, it may be desirable to treat large surface areas of tissue. For example, in treating endometriosis, it is desirable to coagulate large areas of selected body tissue that may be surrounded by other body tissue. Treatment of endometriosis typically involves coagulating tissue that can be located throughout the abdominal cavity. However, due to the inconsistent tissue surfaces presented during such applications, coagulating the desired tissue can be difficult and time-consuming, particularly where large surface areas are involved. A hard, rigid electrode may not easily conform to the tissue surface, thus missing recessed surface areas. Increasing the power may allow recessed areas to be treated in a single pass, but the surrounding tissue, which the user may not want to treat, may be inadvertently impacted by the higher power.
Consequently, there is a need to efficiently coagulate desired body tissue while minimizing harm to surrounding tissue. The present invention satisfies these needs.